Revenue: £129.9m (+17%)
Net profit: 0.5%
It was a busy year for this Portsmouth-based datacentre VAR as it snapped up IBM partner The Portal Partnership and IT and audiovisual rentals firm Hamilton Rentals. The acquisitions added £6.9m to Bell's top line in its year to 31 March 2017, as total revenues hiked 17 per cent on an annualised basis to £129.9m. Founded in 1996, Bell bills itself as a datacentre, workload and cloud migration and optimisation specialist, and has overseas footprints in Hyderabad and Singapore.